When gathering up my scribblings I realised that my poems fall into two camps: those which I've written to entertain and those which I've written to explore the art form. The former tend to be a hit with the majority of my audience (people who claim not to like poetry enjoy hearing or reading them) and the latter have received praise from poets whose work and opinions I respect.
In order to succeed in competitions, I always assume that the judges (respected/acclaimed poets) are looking for something which pushes the art form while recognising the tradition. They want something smart and beautiful which has a tendency to resonate for a long time after it has been read, e.g. Olds' Stag's Leap or McCarthy's The Clothes that escaped the Great War. These poems are mostly for the poets. I suspect that the majority of consumers of the 'high art' poetry are poets themselves.
On the other hand, the enduring poems which win the 'nation's favourite' polls, i.e. the popular poetry, are often easier to understand, have basic metrical schemes and simple end rhymes. They tend to express novel or virtuous philosophical ideas in simple terms, e.g. Kipling's If, Joseph's When I am Old, Eliot's Practical Cats.
It's the popular poetry which works better for performance. Long, wordy poems with elaborate metaphors require multiple readings whereas snappy, humorous verse is immediately pleasing. This accounts, I think, for the success of Kate Tempest and the surge in the popularity of live poetry events.
Poetry competitions tend to want poems for print rather than performance. Often, competitions are run with the intention of publishing a collection or an anthology. These books rarely sell well, which is why literary agents are allergic to poets.
Much as I despise the term, I do think this comes down to branding. Take Tim Key. He made his name on programmes such as Charlie Brooker's Screenwipe, when he would read short, topical poems which were loosely related to the week's news. His poems are funny and easily understood and yet I bought a copy of his first collection on the back of his performances. I enjoyed reading it and shared it with my partner. We both gained pleasure from the reading. I don't expect I'll go back to the poems to re-read them.
There are other books of poems which I keep because I do like to read their contents repeatedly (or at least I think that I would like to re-read them but tend not to as I'm busy reading new stuff instead). I don't see why there shouldn't also be many books of poems which are published as entertainment rather than important tomes, weighty with words of gravity and cleverness. Just as there is a time for jazz, the blues or classical music, so there is a time for fun, bubbly pop. And just as there is a time for important collections of poetry, so there is also a time for the Spike Milligan, the Roald Dahl, the Dorothy Parker and the Tim Key.
As for the poetry competitions, they tend to judge on artistic integrity over entertainment value. So I suppose I know which poems to enter. Or perhaps I should start my own competition?